Effects of Glycosylation of Different Oligosaccharides on Structure and Film-Forming Properties of Soy Protein Isolate

In this study, the performance of soy protein isolate (SPI) films was improved by glycosylation modification to provide a sustainable alternative for food packaging. We systematically explored the effects of different oligosaccharides on the physicochemical properties of SPI films. The experimental results showed that glycosylation significantly enhanced the mechanical strength of the film, with the tensile strength increasing from 1.51 to 3.4 MPa and the elongation at break increasing to 84.15%. Simultaneously, the modified film exhibited excellent barrier properties, and the water vapor transmission rate was significantly reduced, indicating stronger moisture resistance. In addition, thermogravimetric analysis revealed that the xylooligosaccharide-modified film had better thermal stability under high-temperature conditions, and the oxidation resistance test showed that its oxidation resistance rate was as high as 72.46%. In practical applications, xylooligosaccharide-modified films showed excellent performance in strawberry preservation experiments, effectively reducing weight loss and prolonging the edible life. These results not only confirm glycosylation as an effective strategy to enhance the performance of SPI films but also provide a new direction for the development of biodegradable food packaging materials, which have important theoretical and practical application values.